On a Mac: Press and hold the Option key as you start up your Mac. You can change the startup disk once, or for every startup. And the process differs from Intel-based Macs to Apple silicon Macs. You can designate a disk for the Mac to start up from by changing the startup disk with ease. Read more > How to change startup disk on Mac Read this post to learn how to recover after accidentally deleting a startup disk on Mac. Recover Data from Accidentally Deleted Startup Disk on MacĪccidentally deleting Mac startup disk(Macintosh HD) makes all your files stored on the drive lost and could also make the Mac unbootable. If more than one, you can select to boot from a specific disk, especially choose to boot the Mac from an external hard drive when the MacBook won't turn on or there is no startup disk on Mac. Mac will boot from it automatically to turn on. If there is only one internal hard drive, then it is the startup disk. Certainly, it can be other external storage devices that contain macOS for MacBook Air/MacBook Pro/iMac, be it a USB, HDD, SSD, etc. A startup disk is used to boot your Mac, making the computer run normally.īy default, the startup disk is the built-in hard drive on the Mac, known as Macintosh HD. So what is the startup disk on Mac? Read on to know more about it.īy definition, a startup disk, also called a boot disk, is a volume where Mac's operating system and applications are installed. If there is no startup disk, or the startup disk is corrupted, you will fail to boot the Mac to work. Being an essential part of a computer, the startup disk participates in the whole process of your Mac's operation.

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